The surface portion of a golf ball is often coated with a paint composition in order to protect the ball surface or to maintain an attractive appearance. Two-part curing polyurethane paints which are used by mixing together a polyol and a polyisocyanate just prior to application are suitably employed as such golf ball paint compositions for a number of reasons, including their ability to withstand large deformation, impact and abrasion (see, for example, JP-A 2003-253201).
A frequent aim of recent golf ball development has been to further lower the spin rate on full shots taken with a driver. This move toward lower spin rates has engendered a trend toward greater softness in the cover serving as the outermost layer of the ball.
Most golf balls have a core, a cover positioned outside of the core, and a paint film layer positioned outside of the cover. Making this paint film layer soft also often provides certain advantages, such as contributing to stability in the spin rate of the golf ball and imparting outstanding durability (see, for example, JP-A 2011-67595). Additional related art is described in JP-A 2002-53799.
Golf ball paints which use one type of polyester polyol alone as the polyol component have also been developed.
However, the surface of the paint film layer lacks a good abrasion resistance, and so there is room for further improvement.